View Compilation Error

0_0_18493757_12778.cpp: In function 'int main()':
0_0_18493757_12778.cpp:18:30: error: 'strcmp' was not declared in this scope
            if(strcmp(a[k],"0")==0)  break;
                              ^
0_0_18493757_12778.cpp:23:30: error: 'strlen' was not declared in this scope
              d[i]=strlen(a[i]);
                              ^
0_0_18493757_12778.cpp:33:29: error: 'memset' was not declared in this scope
         memset(p,0,sizeof(p));
                             ^